Emrakul, Arena is slow because every turn you want it to take effect, you need to toss down ANOTHER three mana, and even then, it only effects two creatures. Something as simple as Titan's Strength can completely make that card a bad move, and wind up doing nothing more than killing your creature (I'm assuming you would be using this with the Obliterator, but still).

Damnation is a single cast reset button. No regeneration, and unless countered, it just take effect, hence why it is faster.

He was talking about phyrexian arena I think.

Phyrexian arena is slow because it takes many turns to build up an advantage. A T3 arena will only have drawn you two cards by T5 - making it essentially a very slow and more expensive Sign in Blood .

Damnation, on the other hand, affects the board as soon as it is played.

Hey, I know people have suggested a green splash before, and I was just wanting to say that I think your mana base would be fine with 4x Woodland Cemetery and 4x Temple of Malady instead of paying for fetches. I've been playing with a similar deck on Cockatrice, and the Temples are fantastic since the deck is so mana inefficient, and yours probably is too.

I really like this deck. I see that you reset the comments, but have you ever tried/ has anyone mentioned Bloodghast ? I think he would be great in this deck as you could use a solid 2 drop that gives BB (I consider Gatekeeper of Malakir a 3 drop for all purposes sake). I was looking at building this deck but ended up building this deck instead Poor People Obliterator as I already had most of it. I would be curious in running a Mono-black deck sometime.

I think Black Knight Would be a strong two drop. It can block, it has a higher toughness, and it has protection against white, so it's a beautiful starter against white decks. The protection also negates a lot of white removal AND Pacifism which would be a huge negative on this deck (and anything standard). Granted the landfall ability is nice, but I don't think Bloodghast would get there often enough.

I'm too cheap for messengers right now, and I don't have the money for two more obliterators, so I'm subbing with a few knights and they've worked really well so far.

This might not be a great idea; but, why not put Erebos, God of the Dead in the deck? I think that he would be killer against deck with life-gaining abilities. Help me with this case.

As far as matchups, you seem to only have tested against Tier 2 decks. The "decks to beat" per say are URW Control/Midrange, Twin Variants, Affinity, Jund, Scapeshift, UR Storm, etc. Not sure if you have tested against them at all, definitely worth looking into if you haven't.

So I built a slightly cheaper version of this deck (no thoughtseize, a few rain of tears, and only 2 obliterators) and I've been told not to bring it around to my friend's house anymore. Apparently it's just too much of a beat down "You lose this, I gain that" deck that isn't fun to play against...I guess it's doing its job in winning

@junctionIV: Thanks, I've been back & forth with myself on whether to invest in a few, as they would work well against control, however I don't feel comfortable switching anything else out for them.. And I like your B/G variant. If I were to splash another color it would be green..

@CelticStag: I've actually been considering putting some Black Knight s into my sideboard for early artillery against U/W/x Control. The only problem is that I don't know what to replace in my sideboard without compromising my post-board position against other archetypes.. Oh and I find it humbling how this has been inspiring others' to create similar decks with awesome results.. :)

@Spicy526: Actually I used to have a single Erebos in my sideboard, but took it out at some point during one of the various revisions this thing has gone through.. I feel as though he would be all kinds of valuable against U/W/x Control as well, but of course; what to sub out in favor of?

@NateJH: Oddly enough, I'm really not all that spooked out by the archetypes you've mentioned.. Affinity/Robots might be a bit of a toss up, but as far as the others are concerned; I find combo decks(storm, twin, pod, etc..) to be rather easy to break mainboard, and even more-so when you take into account my sideboard options as well.. Also I've squared off with American Control in the past (albeit with another deck), and while being a real threat, it actually scares me the least out of the U/W/x Control variants mostly due to the archetype's reliance on burn.. Also I have played against a serious GP-caliber Jund deck(pre-DRS banning) with an earlier(read: weaker) build of this deck. I lost, but only just barely, and it was really due to Deathrite Shaman .. Scapeshift is the only one I haven't played against at all, but from what I've seen on mtgtop8, it seems to be just a slower, more stable combo with some counterspells to help protect itself.. But maybe I'm missing something, or just delusional, but in either case; would you have any advice to help this deck (hate out the current meta and) take over the world? :P

have you considered shrine to nyx?

@Metroid_Hybrid: I actually have a mono black deck very similar to this one right here that you can check out on my page. It's called Phyrexian Devotion.

I'm just really thanksful I found this deck and decided to run with it. To be honest I was hell bent on getting 4 Obliterators in my deck but I don't even need them. The black knights work great just for a turn 2 vigilence. The White pro is just frosting

Awesome dek. It's what im trying to tune in my deck Paint it Black. which it would be great if you could take a look at it.

See any use for Strionic Resonator

This is my take on Metroid_Hybrid's

How about Nykthos, Shrine to Nyx for the mana base, it gives crazy acceleracion! I myself play a just slightly different deck in modern. Dont put in to many of the bad boys though, you want your colored mana and you dont want to have a "dead" card slot in your hand, since it is legendary. In my experience 2 of them is the perfect amount to assure that it is coming into play but without drawing both too often.

What about Nyxathid with all of that discard it might be worth a play, and two points of devotion

@Ev0clipse: yyyYeahhh.... I've had a lot of suggestions for the Devotion Shrine. Unfortunately the timing of the potential acceleration does very little for this deck as it stands, and would have to change the overall strategy of the deck (by adding high-CMC fatties and/or mana sinks) to get any real benefit from the Shrines..

@Hobbswherescalvin: That (on the other hand..) is actually a fabulous sounding idea! A potential fatty creature that benefits from a attrition-based approach; sweet! He almost seems like a Mono-Black cousin of Tarmogoyf .. This deck is going to be looking different pretty soon ;)

Geth's Verdict it's mono black so I don't see why you wouldn't add this, some creatures are hard to beat unless but not if you force sacrifice them.. Oh and a Ping for one...ya

Hobbs, it's always better to destroy than to make someone sacrifice, because you are giving them the choice. Geth's Verdict wouldn't be terribly great at most aggro decks (where some decks can put down 2-3 creatures per turn if they get the card advantage they need) and this would bomb against any token deck, as they would just off the tokens and keep the real threats.

Victim of Night kills anything that isn't a vampire, werewolf, or zombie (three card types I haven't seen in a while lately, save maybe zombie) and you choose the target, so you can make sure the target you need gone is the one that dies.

Imp's Mischief instead of Sign in Blood for a misdirect ability?

What seems to be your best defense against affinity?

I feel like Bojuka Bog is better then Tormod's Crypt even though you wouldn't be able to play a land after it and it comes in tapped. As soon as it does it's duty it becomes a useful land instead of going to the graveyard

The new rare from 2015 Waste Not might be cool to try out because of all the discarding this deck causes

What about Tormented Thoughts on a creature with a Whip of Erebos out. Using either Nyxathid or Waste Not the amount of discard, and returned benefit could be amazing. It may be a bit too late of game stuff, but I thought the ideas might be amusing. It also would take some pressure from using so much single discard cards. I feel like running all 8 Thoughtseize + Inquisition of Kozilek